Objective: The aim of this study was to investigate the effects of three temporal components of AIDS incidence (i.e., age, period and cohort) on individuals aged 50 or older living in Niteroi, Rio de Janeiro (Brazil). Methods: Age-specific incidence rates were calculated from 1982–2011. Negative binomial and Poisson models were used to analyze the risk of AIDS by age, period and cohort. Results: The risk of AIDS in men was 2.45 times higher than in women, regardless of age and period (p-value < 0.001). The incidence of AIDS in individuals older than 69 years was 7-fold lower than in those aged 50–59 years (p-value < 0.001). A decreasing trend in AIDS risk was observed from the youngest cohort (≥1940) to the oldest (1910–1919). From 1982 to 2006, we could detect an increasing trend in AIDS risk in the population aged 50 years or older. A peak in rates was detected in the period from 2002–2006. The incidence rates in 2002–2006 were six times higher than those in 1987–1991 (p-value < 0.001), independent of age and sex (p-value < 0.001). Conclusions: An increase of AIDS risk in older people was detected. This group should not be neglected by public health programs.